Re: X-aligning on Y-parent - ?? advice needed

[Janek Warchoł]

2013/4/4 Janek Warchoł <address@hidden>:
> Hi Han-Wen,
>
> On Thu, Apr 4, 2013 at 10:48 AM, Han-Wen Nienhuys <address@hidden> wrote:
>> I think this is because these are texts that are attached to multimeasure
>> rests. The multi measure rest is the Y parent of the text. IIRC, the texts
>> are implemented as spanners,
>> so their X parent would be the left bound of the text spanner.
>
> Indeed it seems that this is the case, but i don't see any sense in it.
> It is obvious that MultiMeasureRest itself should be a spanner, but
> its number is just a text, an item with a fixed width.  Why should it
> be a spanner?

Regardless of it being a spanner, i've tried to find where
MultiMeasureRestText's (and MultiMeasureRestNumber's) Xparent is set,
but without sucsess.  I thought that maybe it happens in line 240 of
paper-column-engraver, but apparently not.
I don't know what to do with this.  As i see it, there's something
wrong; it's unclear what happens to these grobs and why they couldn't
have MultiMeasureRests as Xparents, but i don't know how to fix it
because i don't understand what's happening.
Maybe you could give me some pointers?
thanks,
Janek